Beam Mode Quality:By default, the CW lasers in the ≤100 W power range are single-mode with theoretically limited beam quality, typical M2 ≤1.05. However, when the application requires it, multi-mode lasers are also offered. Due to absence of thermal lensing in the laser cavity, fiber lasers maintain beam mode quality and divergence over the full range of output power adjustment. This is not the case with DPSS bulk lasers which are typically optimized to run at nominal power level.

Wavelength Selectivity:The CW fiber lasers in the ≤100 W power range typically have fixed wavelength. Most models allow the user to select the wavelength over a certain range prior to purchase of the laser. For Ytterbium lasers, the typical wavelength range is 1030-1090 nm (Yb CW fiber lasers in the range 978-1020 are also available); for Erbium lasers the range is 1535-1565 nm; for Thulium lasers the range is 1.9-2.05 µm. Green lasers operate near 532± 18 nm. Raman lasers can supply emission in the 1.1-1.8 µm range. Wavelength-tunable lasers are also available on special order.

Polarization:The CW fiber lasers in the ≤100 W power range are offered with either random or linear polarization. Circular polarization is an option for linearly polarized models.

Bandwidth:Typical linewidth is <1 nm for standard mutiline models and is either in the kHz or MHz range for single-frequency options.

Direct Modulation:Direct power modulation in the kHz range is typically available in Ytterbium (1 µm), Erbium (1.5 µm) and Thulium (2 µm) lasers. Green GLR lasers are CW only. External AOM is available on special order.

Power Stability and Optical Noise:Typical power stability is <2% over 4-8 hours under stable environmental conditions (± 2°C).Typical optical noise of standard multiline lasers is 1-2% RMS. Single-frequency models have optical noise an order of magnitude lower.

Optical noise of single-frequency lasers and amplifiers is typically specified as relative intensity noise (RIN) in dB/Hz over a certain frequency range.